<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <div id="test">
        hello world
    </div>
    <!-- innerHTML改变元素的内容 -->
    <!-- textContent -->
    <script>
    var test=document.getElementById("test");
    test.onclick=function(){
        // this.innerHTML="<p>change</p>"
        this.textContent="<p>change</p>"
    }
    </script>
</body>
</html>